HALIFAX, NOVA SCOTIA: The Pentagon's No. 2 will sound out Canada's new government on Friday on its defense plans following Prime Minister Justin Trudeau's election on promises to scrap purchases of F-35 jets and pull Canadian aircraft from strikes on Islamic State.

Deputy Defense Secretary Robert Work said on Thursday that Canada's stance on Lockheed Martin Corp's F-35 programme was not entirely clear.

"We're not certain exactly what the Canadian position is," Work told reporters shortly before landing in Halifax, where he will attend a security forum.

"The Prime Minister has said that he wants to review it. But they have an awful lot of companies in Canada who were going to do work. So we don't know exactly where they're going. So I'm here basically to ask them: 'What is your position?'"

Canada, one of the nine countries in the initial F-35 partnership, pledged to invest $150 million in the programme's development when it signed up in February 2002.

Those funds would not be reimbursed if Canada exits the programme. Many Canadian firms that supply parts worth hundreds of millions of dollars to Lockheed each year could also lose those orders.

"We'd like as many partners in the F-35 programme as possible. But it's up for every country to decide what their defense needs are," Work said, stressing he was not going to lobby Canada's defense minister one way or the other when they meet on Friday.

Trudeau's Liberal party has said it would launch an open and transparent competition to replace Canada's aging CF-18 fighter jets, potentially offering hope to Boeing Co's F/A-18E/F fighters.

Trudeau held his first formal meeting with US President Barack Obama on Thursday in the Philippines, moving to repair relations that had become frayed over the past decade.

Trudeau is much closer politically to Obama than his right-of-centre predecessor, Stephen Harper.

The two leaders agreed on the importance of the US-led campaign against Islamic State but Trudeau vowed to stick to his promise to withdraw six Canadian jets that have been attacking the militants in Iraq and Syria.

Work said he would ask about those plans and about Canada's plans for the mission training security forces in Iraq.

"I'm not here to put pressure on anybody. I'm just here to say: 'Tell me what you're thinking. We're in this together," Work said.